We study the rotating wave patterns in an excitable medium in a disk. This wave pattern is rotating along the given disk boundary with a constant angular speed. To study this pattern we use the wave front interaction model proposed by Zykov in 2007. This model is derived from the FitzHugh-Nagumo equation and it can be described by two systems of ordinary differential equations for wave front an...

Laminar stagnation flow, axi-symmetrically yet obliquely impinging on a rotating circular cylinder, as well as its heat transfer is formulated as an exact solution of the Navier-Stokes equations. Rotational velocity of the cylinder is time-dependent while the surface transpiration is uniform and steady. The impinging stream is composed of a rotational axial flow superposed onto irrotational rad...

We discuss the solution of accretion disk when the black hole is chosen to be rotating. We study, how the fluid properties get affected for different rotation parameters of the black hole. We know that no cosmic object is static in Universe. Here the effect of the rotation of the black hole to the space-time is considered following an earlier work of the author, where the pseudo-Newtonian poten...

The recent detection of the anomalous X-ray pulsar (AXP) 4U 0142+61 in the far infrared with the Spitzer Observatory (Wang, Chakrabarty & Kaplan 2006) constitutes the first instance for a disk around an AXP. Analysis of earlier optical and near infrared data, together with the recent data, implies an active gaseous disk protruding the light cylinder, and not a passive dust disk beyond the light...

For a century, researchers have used the standard lift coefficient C(L) to evaluate the lift, L, generated by fixed wings over an area S against dynamic pressure, ½ρv(2), where v is the effective velocity of the wing. Because the lift coefficient was developed initially for fixed wings in steady flow, its application to other lifting systems requires either simplifying assumptions or complex ad...

Presented in this paper is an analytic approximation to the thermal-fluid problem involving mixed and forced convective heat transfer from a rotating isothermal cylinder placed in a non-uniform stream shear-flow. The approximation is obtained using a series expansion of the scaled boundary layer equations in terms of a boundary layer variable which is directly proportional to the time variable ...